SEA OTTERS THE DIET OF A SEA OTTER IS SEA URCHINS,ABALONE,SNAILS,ANDMUSSELS LS,
Echinoderms Phylum Echinodermata. Include sea stars, sea urchins, sea cucumbers.
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Transcript of Echinoderms Phylum Echinodermata. Include sea stars, sea urchins, sea cucumbers.
EchinodermsPhylum Echinodermata
• Include sea stars, sea urchins, sea cucumbers
• Have radial symmetry based on 5 parts (similar parts surrounding central axis) Planktonic larvae has bilateral symmetry
• Considered to have oral/aboral sides, NOT dorsal/ventral
Body StructureHave a water vascular system-
water filled canals• Tube feet-muscular extensions of
these canals usually end in suckers used for attachment & locomotion
• Ampullae-muscular sacs that sometimes fill tube feet with water• Madreporite-connects vascular
system to outside on aboral (top) surface• Also has gonads & digestive system• No heart, brain or eyes
• Complete digestive tract-stomach, digestive gland & anus• Endoskeleton-covered by a thin
layer of tissue• Surface covered with bumps &
spines giving them their name-”spiny skinned” (echinodermata)
Five classes• 1)sea stars–Class: Asteroidea
• 2)brittle stars–Class: Asteroidea
• Subclass:Ophiuroidea
• 3)sea urchins & sand dollars
• Class: Echinoidea
• 4)sea cucumbers• Class:
Holothuroidea
http://www.youtube.com/watch?v=iSA09qg2BMY&feature=related&safety_mode=true&persist_safety_mode=1&safe=active
• 5)feather stars & sea lilies• Crinoidea
Sea stars (starfish)• 5 arms to 50• Most are predatory- bivalves, snails, barnacle, etc.
Sunflower Star http://www.youtube.com/watch?v=ALaMoS_vvNE&safety_mode=true&persist_safety_mode=1&safe=active
Cushion Star
Brittle Stars• Arms very long & flexible-tube feet lack suckers• Eat particles oforganic matter passed from feet to mouth• More species than any other group of echinoderms
Basket Star (Brittle Star)
Brittle Stars
Sea Urchins & Sand Dollars
• Filter feed on drifting plant/animals• Deposit feeders that live on bottoms using tube feet lined with mucus to pick up particles
Sea Urchins
Sand Dollars
Sea Cucumbers• Wormlike, lack spines • Tube feet around mouth reach out and pick up organic material• Escapes by ejecting digestivesystem distracting predators
Sea Cucumberhttp://video.nationalgeographic.com/video/kids/animals-pets-kids/invertebrates-kids/sea-cucumber-kids/
http://www.youtube.com/watch?v=aCxKFc3XtJs&safety_mode=true&persist_safety_mode=1&safe=active
Feather stars & Sea lilies• 5 to 200 arms due to the branching• Mucus helps in catching food• Some attach to bottom, some crawl on surfaces in shallow to deep water
Sea Lilies (with Stalks)
Feather Stars (noStalks
http://www.youtube.com/watch?v=7V_px48dob8&safety_mode=true&persist_safety_mode=1&safe=active
Biology• Sexes are separate in most
echinoderms• External fertilization• Spawning occurs at once to increase
survival
• Echinoderms can use regeneration to replace missing parts• In some sea stars a severed arm
can grow into a complete individual
http://www.youtube.com/watch?v=rE8l-KFQlhY&safety_mode=true&persist_safety_mode=1&safe=active